A former Royal Grammar School student in the city, the scrum half made his first team full debut in the top-flight in 2008. Arr also won international honours that season as he was a part of the England Under-20 team that achieved the Grand Slam.
The 24-year-old was rewarded for his outstanding form in 2009/10 when he picked up the Young Player of the Year and Most Improved Player of the Year awards.
Twelve months later he went one better as he was named the Player-of-the-Year at the club's end of season dinner after his impressive role helping Warriors win promotion back to the Aviva Premiership.
Arr became a Warriors centurion when he made his one hundredth appearance for the club against Leicester Tigers in September 2012.
Arr said: "I'm delighted to sign and extend my career at Warriors. I truly feel we are on the verge of moving on and it does feel like something is now happening at Warriors that can make the difference.
"I've seen a lot of things change for the better during my time here and this season we have been competitive in every game we have played. I don't feel we are far away from breaking the mould here.
"We were all disappointed to miss out on the quarter-finals of the Amlin Challenge Cup, but we still have chance to progress in the LV= Cup and move up the league table.
"What is crucial to me is that I feel I still have so much to achieve here, the job is not complete and I want to be part of bringing real success to Sixways."
Head Coach Richard Hill said: "Jonny is an outstanding scrum half. He is technically very good in terms of his passing, kicking and defence. He plays a quick game which suits our attacking game.
"He has really come back into the selection frame as our attacking playing style has evolved. He gets the ball away from the breakdown quickly and so has come into his own.
"Jonny's way of playing really suits the multi-phase and fast game we want to play and I'm sure his strengths will continue to be a huge asset to Warriors in the coming years."